Polyols derived from farnesene for polyurethanes

ABSTRACT

A composition is provided for making a polyurethane that may be incorporated in various products, such as a sealant, a coating, a caulk, an electric potting compound, a membrane, a sponge, a foam, an adhesives, and a propellant binder. The composition includes one or more polyols, one or more isocyanate-group containing compounds having an isocyanate group functionality of at least two, and optionally one or more chain extenders. At least one of the polyols is a farnesene-based polyol having a number average molecular weight less than or equal to 100,000 g/mol and a viscosity at 25° C. less than 10,000 cP. The farnesene-based polyol may be a homopolymer or a copolymer of farnesene. The composition may also comprise additional polyols, such as a polyol of a homopolymer or copolymer of a polydiene. Methods of preparing a polyurethane are also provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.14/989,140, filed on Jan. 6, 2016, which are incorporated herein byreference in its entirety for all purposes.

FIELD OF THE INVENTION

The invention relates to polyurethanes that may be used as insulatingglass sealants, electric potting compounds, constructioncoating/sealants, and water membranes, for example. More specifically,the invention relates to polyurethanes and their compositions that arederived or include polyols derived from farnesene.

BACKGROUND

It is well known to prepare isocyanate terminated polyurethaneprepolymers from polyether and/or polyester polyols and aromaticdiisocyanates. Polyurethane prepolymers are formed by combining anexcess of diisocyanate with polyol. One of the —NCO groups of adiisocyanate reacts with one of the OH groups of the polyol, and theother end of the polyol reacts with another diisocyanate. The result isa prepolymer having an isocyanate group on both ends. The prepolymer istherefore a diisocyanate itself, but unlike the original diisocyanate,the prepolymer has a greater molecular weight, a higher viscosity, alower isocyanate content by weight (% NCO), and a lower vapor pressure.

Furthermore, it is also well known to prepare polyurethane elastomers bychain extending these prepolymers with low molecular weight diols. Theresulting polyurethanes have excellent mechanical properties, but arerather hydrophilic, which can limit their utility in certain moisturesensitive applications.

Hydroxyl terminated polyols with very non-polar backbones (e.g.,hydroxyl functional polybutadiene) can be used to introducehydrophobicity into polyurethane elastomers. However, polyols having apolybutadiene backbone, for example, usually have a much higherviscosity than those based on polyether backbone. To reduce theviscosity of hydroxyl-terminated polybutadienes, one can either blendpolyether polyols into the polyol mixture or make prepolymers withincreased —NCO percentage. The approach is in general not ideal becausethe final polyurethane products tend to have inferior hydrophobicity.

Thus, there is a need for improved polyurethanes having relatively lowviscosity for easier application that are hydrophobic formoisture-sensitive applications.

SUMMARY OF THE INVENTION

According to one embodiment, a composition is provided for making apolyurethane. The composition comprises one or more polyols, one or moreisocyanate-group containing compounds having an isocyanate groupfunctionality of at least two, and optionally one or more chainextenders. At least one of the polyols is a farnesene-based polyolhaving a number average molecular weight less than or equal to 100,000g/mol, more desirably a number average molecular weight less than orequal to 25,000 g/mol, and a viscosity at 25° C. less than 10,000 cP.The farnesene-based polyol may be a polyol of a farnesene homopolymer ora copolymer of farnesene and, optionally, one or more dienes and/orvinyl aromatics. Examples of dienes include butadiene and isoprene. Thechain extender may include one or more monomeric polyols and/orpolyamines. The composition may also comprise additional polyols, suchas a polyol of a homopolymer or copolymer of a polydiene. The NCO/OHratio of the composition may be about 2:1 to 1:2.

According to another embodiment, a method of preparing a polyurethane isprovided comprising combining one or more polyols with one or moreisocyanate-containing compounds having a isocyanate functionality of atleast two, and optionally, a chain extender, to form a mixture andcuring the mixture. At least one of the one or more polyols is afarnesene-based polyol. The chain extender may be one or more monomericpolyols and/or polyamines, such as 1,4-butanediol, 1,6-hexanediol,ethylene glycol, 2-ethyl-1,3-hexanediol (EHD),2-butyl-2-ethyl-1,3-propanediol (BEPG), 2,2,4-trimethyl-1,3-pentanediol(TMPD), 2,4-deithyl-1,5-pentanediol (PD-9), N,N-diisopropanol aniline,dimethylolpropionic acid, hydroquinone dihydroxyethyl ether (HQEE),diethylene glycol, propylene glycol, trimethylolpropane, glycerol,diethyltoluenediamine (DETDA), 4,4′-methylene bis(2-chloroaniline)(MBCA), ethylenediamine (EDA), dimethylthiotoluene-diamine (DMTTDA),4,4′-methylenedianiline (MDA), complex of methylenediamine with NaCl(MDA complex), trimethyleneglycol di-p-aminobenzoate (TMGDAB),4,4′-methylene-bis(3-chloro-2,6-diethylaniline) (M-CDEA), andN,N′-bis(sec-butyl)methylene-dianiline (SBMDA). The one or moreisocyanate-group containing compounds include 4,4′-diphenylmethanediisocyanate (MDI), cyclohexanediisocyanate, p-phenylene diisocyanate,1,5-naphthalene diisocyanate, toluene diisocyanate (TDI), p-xylenediisocyanate, hexamethylene diisocyanate, 4,4′-dicyclohexylmethanediisocyanate, 1,4-bis(isocyanomethyl)-cyclohexane, p-tetramethylxylenediisocyanate, m-tetramethylxylene diisocyanate, isophorone diisocyanate,and combinations thereof.

According to yet another embodiment, a polyurethane is provided preparedaccording to the methods disclosed herein. An elastomeric product isalso provided comprising the polyurethane that may be in the form of asealant, a coating, a caulk, an electric potting compound, a membrane, asponge, a foam, an adhesives, and a propellant binder.

These and other aspects of the various embodiments of the disclosedmethods and compositions will be understood from the following detaileddescription.

DETAILED DESCRIPTION OF THE INVENTION

According to various embodiments of the disclosed methods andcompositions, a farnesene-based polyol is provided, as well as acomposition for making a polyurethane comprising a diisocyanate and thefarnesene-based polyol. The composition may further include chainextenders, such as monomeric polyols and polyamines. Therefore, as usedherein “polyurethane” refers to a polymer containing one or moreurethane bonds and may also include one or more urea bonds.

The farnesene-based polyols according to the disclosed methods andcompositions exhibit lower viscosities compared to polydiene-basedpolyols, such as polybutadiene, of similar molecular weight. Therefore,farnesene-based polyols may be handled favorably in polyurethaneformulations and applications without significant dilution with othercomponents. In addition, the farnesene-based polyols can be combinedwith oligomers based on hydroxyl-terminated polybutadiene andpolyisoprene to provide polyol mixtures that may be combined with one ormore diisocyanates to form the compositions for making thepolyurethanes. The viscosity of polyfarnesene may be controlled bycopolymerization with other monomers, such as dienes and vinylaromatics. Examples include butadiene, isoprene, and styrene. Theresulting polyurethanes derived from polyfarnesene polyols, havingexcellent hydrophobicity, are excellent in a variety of applications,such as insulating glass sealants, caulks, electric potting compounds,construction coating/sealants, water membranes, sponges, foams,adhesives, coatings, propellant binders, encapsulating compounds, aswell as other rubber-fabricated materials.

The farnesene-based polyol may be obtained by polymerizing a monomerfeed that primarily includes farnesene followed byhydroxyl-functionalization of the terminal end(s) of the polymer. Asused herein “polyol” is an organic compound having more than onehydroxyl group. The farnesene-based polymers have a lower viscositycompared to polybutadienes, but comparable hydrophobicity. Therefore,the polyols may be used to manufacture polyurethanes used in moisturesensitive coating applications, for example, without significantdilution with other additives for the purpose of lowering its viscosity.

Any methods known by those having skill in the art may be used topolymerize the farnesene monomers. Anionic polymerization may bedesirable because anionic polymerization allows greater control over thefinal molecular weight of the polymer. The living terminal ends of thepolymer may also be easily quenched using an epoxide followed by contactwith a protic source providing a polyol. The low viscosityfarnesene-based polymers may be derived by polymerizing farnesenemonomer alone or with at least one other monomer, such as butadiene orisoprene, for example. It is preferred that the polymers made accordingto various embodiments of the disclosed methods and compositions arederived from a monomer feed that is primarily composed of farnesene.

Farnesene exists in isomer forms, such as α-farnesene((E,E)-3,7,11-trimethyl-1,3,6,10-dodecatetraene) and β-farnesene(7,11-dimethyl-3-methylene-1,6,10-dodecatriene). As used in thespecification and in the claims, “farnesene” means (E)-β-farnesenehaving the following structure:

as well (E)-β-farnesene in which one or more hydrogen atoms have beenreplaced by another atom or group of atoms (i.e. substituted).

The farnesene monomer used to produce various embodiments of the polymeraccording to the disclosed methods and compositions may be prepared bychemical synthesis from petroleum resources, extracted from insects,such as Aphididae, or plants. Therefore, an advantage of the disclosedmethods and compositions is that the polymer may be derived from amonomer obtained via a renewable resource. The monomer may be preparedby culturing a microorganism using a carbon source derived from asaccharide. The farnesene-based polymer according to the disclosedmethods and compositions may be efficiently prepared from the farnesenemonomer obtained via these sources.

The saccharide used may be any of monosaccharides, disaccharides, andpolysaccharides, or may be a combination thereof. Examples ofmonosaccharides include, without limitation, glucose, galactose,mannose, fructose, and ribose. Examples of disaccharides include,without limitation, sucrose, lactose, maltose, trehalose, andcellobiose. Examples of polysaccharides include, without limitation,starch, glycogen, and cellulose.

The cultured microorganism that consumes the carbon source may be anymicroorganism capable of producing farnesene through culturing. Examplesthereof include eukaryotes, bacteria, and archaebacteria. Examples ofeukaryotes include yeast and plants. The microorganism may be atransformant obtained by introducing a foreign gene into a hostmicroorganism. The foreign gene is not particularly limited, and may bea foreign gene involved in the production of farnesene because it canimprove the efficiency of producing farnesene.

In the case of recovering farnesene from the cultured microorganism, themicroorganism may be collected by centrifugation and disrupted, and thenfarnesene can be extracted from the disrupted solution with a solvent.Such solvent extraction may appropriately be combined with any knownpurification process such as distillation.

The farnesene-based polymers described herein may be prepared by acontinuous solution polymerization process wherein an initiator,monomers, and a suitable solvent are continuously added to a reactorvessel to form the desired homo-polymer or co-polymer. Alternatively,the farnesene-based polymers may be prepared by a batch process in whichall of the initiator, monomers, and solvent are combined in the reactortogether substantially simultaneously. Alternatively, thefarnesene-based polymers may be prepared by a semi-batch process inwhich all of the initiator and solvent are combined in the reactortogether before a monomer feed is continuously metered into the reactor.

Preferred initiators for providing a polymer with living terminal chainends include, but are not limited to organic salts of alkali metals. Thepolymerization reaction temperature of the mixture in the reactor vesselmay be maintained at a temperature of about −80 to 80° C.

As understood by those having skill in the art, anionic polymerizationmay continue, as long as monomer is fed to the reaction. Thefarnesene-based polyols may be obtained by polymerization of farneseneand one or more comonomers. Examples of comonomers include, but are notlimited to, dienes, such as butadiene, isoprene, and myrcene, or vinylaromatics, such as styrene and alpha methyl styrene, in which butadiene,isoprene, and styrene are preferred. In one embodiment of the disclosedmethods and compositions, a method of manufacturing a farnesene-basedpolyol may comprise polymerizing a monomer feed, wherein the monomerfeed comprises farnesene monomer and a comonomer in which the comonomercontent of the monomer feed is ≤75 mol. %, alternatively ≤50 mol. %, oralternatively ≤25 mol. %, based on the total moles of the monomer in themonomer feed. Examples of comonomers include, but are not limited to,dienes, vinyl aromatics, and combinations thereof.

The hydroxy functionalized low viscosity farnesene-based homo-polymersor co-polymers according to embodiments of the disclosed methods andcompositions may have a number average molecular weight less than orequal to 100,000 g/mol, alternatively less than or equal to 25,000g/mol, as measured through a gel permeation chromatograph and convertedusing polystyrene calibration. The weight of the polyol can be fromabout 0.5 wt. % to about 99.5 wt. % of the resulting polyurethane. Thefarnesene-based homopolymers or copolymers may have a viscosity lessthan or equal to 100,000 cP, alternatively less than 50,000 cP, oralternatively less than or equal to 25,000 cP, at 25° C.

The quenching step to end polymerization is accomplished by reacting thea living terminal end(s) of the living polymer with an alkylene oxide,such as propylene oxide, and a protic source, such as an acid, resultingin a diol or polyol, i.e. a hydroxyl group on the terminal ends of thepolymer.

Following polymerization, the hydroxyl-terminated polymer may behydrogenated to decrease the degree of unsaturation of the polymer to atmost 50%, alternatively at most 10%. Hydrogenation of thehydroxyl-terminated polymer will modify the glass transition temperature(Tg) of the polymer and improve the thermostability and UV-stability ofthe polymer. Hydrogenation may be carried out by a variety of processesfamiliar to those of ordinary skill in the art including, but notlimited to, hydrogenation in the presence of catalysts, such as RaneyNickel, nobel metals, soluble transition metal catalysts, and titaniumcatalysts, for example. Degree of unsaturation is determined byanalytical methods known in the art, such as iodine value.

According to certain embodiments, a composition for making apolyurethane is provided that comprises one or more polyols, wherein atleast one polyol is a farnesene-based polyol, one or moreisocyanate-group containing compounds having a functionality of at least2, and optionally, a chain extender selected from the group consistingof monomeric polyols, polyamines, and combinations thereof. The amountof at least one polyol and one or more isocyanate-group containingcompounds in the composition may be such that the ratio of —NCO groupsto —OH groups is about 2:1 to 1:2. The use of NCO/OH ratios lower thanunity results in softer, lower modulus materials. At NCO/OH ratio levelsabove 1.0 lower modulus material may also be prepared. However, thesematerials will gradually increase in hardness with time since the freeNCO groups can undergo further reaction with moisture to give ureastructures, or can form allophanate crosslinks (especially at elevatedtemperatures).

The physical properties of the polyurethane, such as viscosity, may betailored depending on the desired application for the polyurethane byselection of the molecular weight of the polyols, as well as the ratioof farnesene-based polyols to non-farnesene-based polyols in thecompositions described herein. Additional polyols that may also beincluded in the composition with the farnesene-based polyol include, butare not limited to, poly(oxypropylene)glycol, poly(oxyethylene)glycol,poly(oxypropylene-oxyethylene)glycol, poly(oxytetramethylene)glycol,poly(oxybutylene)glycol, poly(caprolactone)glycol,poly(ethyleneadipate)glycol, poly(butyleneadipate)glycol, aromaticpolyester glycols, polybutadiene polyol, hydrogenated polybutadienepolyol, polyisoprene polyol, hydrogenated polyisoprene polyol, andmixtures thereof.

The one or more isocyanate-group containing compounds having afunctionality of at least 2 may exhibit several or all of the followingcharacteristics: bulk, symmetry around the isocyanate functional groups,rigid, aromatic, crystalline and high purity. The one or moreisocyanate-group containing compounds having a functionality of at least2 include, but are not limited to, 4,4′-diphenylmethane diisocyanate(MDI), cyclohexanediisocyanate, p-phenylene diisocyanate,1,5-naphthalene diisocyanate, toluene diisocyanate (TDI), p-xylenediisocyanate, hexamethylene diisocyanate, 4,4′-dicyclohexylmethanediisocyanate, 1,4-bis(isocyanomethyl)-cyclohexane, p-tetramethylxylenediisocyanate, m-tetramethylxylene diisocyanate, isophorone diisocyanate,and mixtures thereof.

The one or more chain extenders included in the composition may includemonomeric polyols and polyamines, for example. The molecular weight ofeach of the one or more chain extenders may be about 50 to 700. Asunderstood by those of skill in the art, the type and amount of chainextender will affect the elastomeric properties of the polyurethane,such as tensile strength, elongation, and tear resistance values. Whenthe compositions as described herein react to form a polyurethane, thechain extenders contribute to the hard segment of the polyurethane thatserve as physical cross-links between the amorphous soft segmentdomains. The hard segments, which are formed by the reaction between anisocyanate group and either the hydroxyl or amine group of the chainextenders, inhibit plastic flow of softer segments of the polyurethaneprovided by the long chain polyols. The choice and amount of chainextender may also affect flexural, heat, and chemical resistanceproperties of the polyurethane. The chain extenders may include, but arenot limited to, 1,4-butanediol, 1,6-hexanediol, ethylene glycol,2-ethyl-1,3-hexanediol (EHD), 2-butyl-2-ethyl-1,3-propanediol (BEPG),2,2,4-trimethyl-1,3-pentanediol (TMPD), 2,4-deithyl-1,5-pentanediol(PD-9), N,N-diisopropanol aniline, dimethylolpropionic acid,hydroquinone dihydroxyethyl ether (HQEE), diethylene glycol, propyleneglycol, trimethylolpropane, glycerol, diethyltoluenediamine (DETDA),4,4′-methylene bis(2-chloroaniline) (MBCA), ethylenediamine (EDA),dimethylthiotoluene-diamine (DMTTDA), 4,4′-methylenedianiline (MDA),complex of methylenediamine with NaCl (MDA complex), trimethyleneglycoldi-p-aminobenzoate (TMGDAB),4,4′-methylene-bis(3-chloro-2,6-diethylaniline) (M-CDEA),N,N′-bis(sec-butyl)methylene-dianiline (SBMDA), and mixtures thereof.

The polyurethanes made according to the methods disclosed herein may bemanufactured by a batch procedure or a continuous procedure. The mixingof the reactants can be accomplished by any of the procedures andapparatus conventional in the art. The individual components areurethane grade and, as such, have low moisture content or are renderedsubstantially free from the presence of water using conventionalprocedures, for example, by azeotropic distillation, or by heating underreduced pressure at a temperature in excess of the boiling point ofwater at the pressure employed. The later procedure is desirable toaccomplish degassing of the components.

Preparation of polyurethanes according to the various embodimentsdisclosed herein may be achieved by procedures conventional in the artfor synthesis of polyurethanes. Such procedures include the castingprocedure in which the reactants (one or more polyols, one or morediisocyanates, and one or more optional chain extenders) are mixed inthe liquid state, either by the one-shot route or the two-step route,also known as the prepolymer technique, and then, the reacting mixtureis fabricated into its final form by an appropriate technique such ascasting or molding, while the reaction continues by chain extensionand/or cross-linking. Final cure is typically achieved by a hot airpost-cure for up to twenty-four hours at 25° C. to about 200° C. Ingeneral, the reaction of the components limits the subsequent pot lifeto several minutes, and subsequent casting or molding immediatelythereafter. Vacuum degassing may also be used to prepare castings whichare bubble free. In the one-shot route, the polyurethane is made bycombining all of the components of the composition for making apolyurethane as described herein generally simultaneously into a commonreaction vessel. One-shot systems offer the advantages of versatility,simplicity, and low cost fabrication techniques for preparing urethaneshaving a wide range of physical properties. Such applications as caulks,sealants, elastomers and foams are possible via these systems.

Two-shot systems are based upon the intermediate formulation of aprepolymer which can be further chain-extended with additional polyolsand polyamines to form the final polyurethane. These systems may providehigher performance urethanes and have the advantages of lowering theoverall toxicity of the system.

In the prepolymer procedure, the one or more isocyanate-group containingcompounds are first reacted with the one or more polyols to form aprepolymer. The one or more polyols include at least one farnesene-basedpolyol. Therefore, the resulting prepolymer is a polymer having a chainderived from farnesene monomer and terminal ends functionalized with oneor more isocyanate groups. Additional isocyanate-group containingcompounds, polyols, and chain extenders may then be added to theprepolymer to complete formation of the polyurethane.

The methods described herein may be either solventless or include asolvent. In the solventless embodiment, the one or more polyols areheated to 70° to 100° C., for example, and then thoroughly mixed withthe desired amount of chain extender for at least two hours undernitrogen flow to eliminate moisture. Isocyanate containing compounds arethen added to the mixture immediately prior to pouring the mixture intoa heated mold, desirably treated with a mold release compound. Thepolyurethane composition is formed by curing into the mold for severalhours and then postcuring above 110° C. for at least 2 hours. In thesolvent method, the one or more polyols are dissolved in a solvent, suchas dry toluene, heated to about 70° to 100° C., for example, and thenmixed with the desired type and amount of the one or moreisocyanate-containing compounds and chain extenders for at least 2 hoursunder nitrogen flow. The solvent is then removed by evaporation, forexample, and then the composition is postcured for at least 2 hours at110° C. while under vacuum. The thermoplastic polyurethane compositioncan then be heat pressed above the elastomer melting point to form anelastomeric polyurethane article.

The compositions for making a polyurethane, in addition to including oneor more polyols, isocyanate-containing compounds, and chain extendersmay also include reinforcing additives, asphalt, and process oils toalter the physical characteristics of the polyurethane compositionand/or reduce costs.

Plasticizers may be included as extenders that also increase thesoftness and flexibility of the cured material in various embodiments ofthe disclosed methods and compositions. One or more plasticizers may beselected from the group consisting of vegetable oil, mineral oil,soybean oil, terpene resins, aromatic esters (e.g. dioctyl phthalate,diundecyl phthalate, tricresyl phosphate, and triisononyl mellitate),linear esters (e.g. di-tridecyl adipate), chlorinated Paraffin, aromaticand napthenic process oils, alkyl naphthalenes, and low molecular weightpolyisoprene, polybutadiene, or polybutylene resins. The amounts ofplasticizer employed in the invention composition can vary from 0 toabout 500 phr (per hundred parts of polyurethane), between about 0 toabout 100 phr, and most between about 0 and about 60 phr.

Because of their hydrocarbon backbones, the polyurethanes made accordingto the methods and compositions described herein are compatible withconventional hydrocarbon oils, chlorinated oils, asphalts and otherrelated low cost extending materials. The quantity of asphalt or processoil which may be incorporated depends on the type of oils, the amount ofisocyanate groups present, and the type of fillers, if present. Curedpolyurethanes may be formulated which incorporate in excess of 100 partsextending material per 100 parts of polyurethane and do not “bleed” oilfrom the final product. The cured polyurethanes may also exhibit amoderate decrease in tensile strength and modulus and improvedelongation with the addition of an extending material. Oil extension mayalso improve hydrolytic stability, control of premix viscosities, potlife, gel time, cure time, and the ability to attain higher fillerloading. The use of materials such as chlorinated waxes and oils alsoprovides fire retardant properties to the finished product.

Suitable fillers include, but are not limited to, carbon black, calciumcarbonate, clays, talcs, zinc oxide, titanium dioxide, silica and thelike. Calcium carbonates are relatively soft and may be used at ratherhigh levels to enhance the extrusion properties of the polyurethanecompositions described herein. Elastomers prepared using calciumcarbonates are suitable for many caulk and sealant applications wherehigh elongation and moderate tensile properties are required. Clays mayprovide a moderate degree of reinforcement, fair abrasion resistance,but a relatively high stiffening effect. Clays are used as fillers instocks requiring hardness and high modulus; e.g., shoe soles and heels,mats, and floor tiles. Zinc oxide may also provide resilience and heatconductivity, but its use as a reinforcing filler may be limited due tohigh density and cost. Zinc oxide may be effectively employed as areinforcing filler in conjunction with carbon black to increase tensile,modulus, tear, and hardness, and abrasion resistance. It is important tonote that at a constant carbon black level, increasing the concentrationof zinc oxide may decrease the workable pot life of the compositionsdescribed herein after the isocyanate component is added; i.e., gelationoccurs more rapidly. Silicas contribute a greater increase in tensilestrength than other non-carbon black fillers. Silicas also have aprofound stiffening effect on the compositions described herein. Theamount of filler usually is in the range of 0 to about 800 phr,depending on the type of filler used and on the application for whichthe formulation is intended. Preferred fillers are silica and titaniumdioxide. The filler should be thoroughly dried in order that adsorbedmoisture will not interfere with the reaction between theisocyanate-containing compounds and the one or more polyols.

Stabilizers known in the art may also be incorporated into thecomposition. For example, adhesive formulations that utilize thepolyurethanes of the disclosed methods and compositions may includestabilizers for protection during the life of the sealant or adhesiveagainst, for example, oxygen, ozone and ultra-violet radiation. Thestabilizers may also prevent thermo-oxidative degradation duringelevated temperature processing. Antioxidants and UV inhibitors whichinterfere with the urethane curing reaction should be avoided. Preferredantioxidants are sterically hindered phenolic compounds, like butylatedhydroxy toluene. Preferred UV inhibitors are UV absorbers such asbenzotriazole compounds. The amount of stabilizer in the formulationwill depend greatly on the intended application of the product. Ifprocessing and durability requirements are modest, the amount ofstabilizer in the formulation will be less than about 1 phr. Howeverdepending on the intended use of the polyurethane, the stabilizerconcentration may be as much as about 10 phr.

The polyurethane according to the embodiments of the disclosed methodsand compositions may be cured by procedures known by those havingordinary skill in the art for the curing of isocyanate terminatedpolymers. Curing mechanisms include, but are not limited to, the use ofmoisture, blocked amines, oxazolidines, epoxies, triisocyanurate ringformation, allophonate and biruet crosslinking and the like. Unfilledurethane systems may be cured at ambient temperatures, but cure ratesmay be accelerated by using either typical urethane catalysts and/orelevated temperatures. Catalysts include, but are not limited to,dibutyltin dilaurate and 1,4-diazo [2.2.2] bicyclooctane. The amount andtype of catalyst that may be included in the compositions describedherein may be selected based on the desired cure rate. Dependent uponthe curing technology employed, the resulting polyurethanes may beeither a thermoset polyurethane or a higher melt temperaturethermoplastic polyurethane once curing is accomplished.

The polyurethanes obtained according to the various embodiments of thedisclosed methods and compositions exhibit excellent chemical andphysical properties.

EXAMPLES

Embodiments of the disclosed methods and compositions are furtherdescribed using the following non-limiting examples.

Table 1 provides a list of the materials used for preparing theformulations of the following examples and comparative examples.

TABLE 1 Material Description Eq. Wt Krasol ® LBH 2000 LO (polybutadiene0.812 meq/g OH value 1232 diol) (27-74) Krasol ® HLBH P-2000(hydrogenated 0.83 meq/g OH value polybutadiene diol) Poly bd ® R45-HTLO(polybutadiene 0.84 meq/g OH value diol) Polyfarnesene diol (Mw = 2000)1.019 meq/g OH value 981 (27-74) 2-ethyl-1,3-hexanediol EHD, 73.12 2,4′Diphenylmethane Diisocyanate 33.5% NCO content 125.4 (Lupranate ® MI)Dibutyltin dilaurate T-12 Dibutyl phthalate DBPEvaluation of Effect of Polyol Blends and Isocyanate Content

The effect of blending a polyfarnesene diol and polybutadiene diol andreacting the various blends with increasing amounts of a diisocyanatewere evaluated. In Comparative Examples 1-3, only polybutadiene diolswas used. In Examples 1-6, blends of polybutadiene diol and polyfarnesediols were used. Viscosity of the polyurethane prepolymers was measuredat 25° C., and NCO group content was monitored by identifying theintensity of NCO group absorbance peaks at 2265 cm⁻¹ on IR duringprepolymer preparation at 60° C. for 3 hours. The results are providedin Tables 2, 3, and 4.

TABLE 2 Comp. Ex. 1 Ex. 1 Ex. 2 Krasol ® LBH 2000 LO 100 75 50Polyfarnesene diol 0 25 50 2,4′ Diphenylmethane Diiso- 19.95 20.09 20.24cyanate Free NCO % in final prepolymer 2.72 2.58 2.43 by wt % Viscosityof prepolymer at 25° C., cps At initial time of prepolymeriza- 3437 22301398 tion At reacted 3 hrs of polymeriza- Off 241000 131000 tion scaleNCO content from intensity at 2265/cm on FTIR At initial time ofprepolymeriza- 0.1978 0.2074 0.2137 tion At reacted 3 hrs of polymeriza-0.0950 0.0927 0.0911 tion

TABLE 3 Comp. Ex. 2 Ex. 3 Ex. 4 Krasol ® LBH 2000 LO 100 75 50Polyfarnesene diol 0 25 50 2,4′ Diphenylmethane Diiso- 31.49 31.63 31.79cyanate Free NCO % in final prepoly- 5.42 5.28 5.15 mer by wt %Viscosity of prepolymer at 25° C., cps At initial time of prepolymer-2007 1299 870 ization At reacted 3 hrs of polymer- 69360 39492 22620ization NCO content from intensity at 2265/cm on FTIR At initial time ofprepolymer- 0.2976 0.2962 0.2982 ization At reacted 3 hrs of polymer-0.2001 0.1985 0.1969 ization

TABLE 4 Comp. Ex. 3 Ex. 5 Ex. 6 Krasol ® LBH 2000 LO 100 75 50Polyfarnesene diol 0 25 50 2,4′ Diphenylmethane Diiso- 46.19 46.33 46.48cyanate Free NCO % in final prepolymer 8.24 8.12 7.99 by wt % Viscosityof prepolymer at 25° C., cps At initial time of prepolymeriza- 1119 721545 tion At reacted 3 hrs of polymeriza- 19371 10685 7264 tion NCOcontent from intensity at 2265/cm on FTIR At initial time ofprepolymeriza- 0.3821 0.3827 0.3852 tion At reacted 3 hrs of polymeriza-0.3048 0.3057 0.3063 tion

Based on the results in Tables 2-4, increased polyfarnesene diol in thepolyol blends resulted in a lower viscosity of the resultingpolyurethane prepolymer.

Similar viscosity results, provided in Tables 5, 6, and 7 were exhibitedby various blends of polyfarnesene diols with polybutadiene diols. Theviscosity of the blends decreases with the increased amount ofpolyfarnesene diol in the blends.

TABLE 5 Polyfarnesene diol 100 75 50 25 0 Polybd R45HTLO 0 25 50 75 100Brookfield 25° C. 1289 1828 2757 4187 6467 viscosity, cps 40° C. 427 6661060 1687 2663 60° C. 142 236 398 652 1045 miscible miscible miscible

TABLE 6 Polyfarnesene 100 75 50 25 0 diol Krasol LBH 2000 0 25 50 75 100Brookfield 25° C. 1289 2128 3609 6186 10623 viscosity, cps 40° C. 427668 1035 1629 2605 60° C. 142 205 299 434 631 miscible miscible miscible

TABLE 7 Polyfarnesene 100 75 50 25 0 diol Krasol HLBH 0 25 50 75 1002000 Brookfield 25° C. 1289 2820 6452 15216 36492 viscosity, cps 40° C.427 863 1804 3819 8748 60° C. 142 254 473 892 1831 miscible misciblemiscibleEvaluation of Physical Properties

The polyfarnesene diol (Mw=2000) was used, either by itself or blendedwith polybutadiene polyol, to prepare various samples of curedpolyurethane plaques for evaluation. The polyurethanes were preparedfrom blends that also used various concentrations of a chain extender,ethyl hexanediol (EHD), and a diisocyanate 2,4′ DiphenylmethaneDiisocyanate (Lupranate® MI).

The polyurethanes were prepared by the one shot procedure. Polyols andchain extenders were combined in a flask and mixed under nitrogen atambient temperature followed by the addition of isocyanate andimmediately pouring the mixture into a heated mold. The final curing wasperformed in an oven and held at 85° C. for 5 hours and overnight at 60°C. Each sample sheet was post cured for one week at room temperaturebefore testing of its physical properties. Relative parameters weretested by referring to ASTM D412, ASTM D624 Die C, and using DSC, Shoretype Durometers, a Brookfield viscometer, and an EJA Vantage-10 tensiletester and the results provided in Tables 8, 9, and 10.

TABLE 8 Comp. Ex. A1 A2 A3 A4 Krasol LBH 2000 LO 100 75 50 0  Polyfarnesene diol 0 25 50 100    2-ethyl-1,3-hexanediol 5.34 5.05 4.75 4.10 2,4′ Diphenylmethane 19.95 20.09 20.24 20.42 Diisocyanate 20% T-12solution in DBP, 4 4 4 4   drops Hard segment content, 20.19 20.09 19.9919.69 wt % Hardness of PU, Shore A 54 47 38 55*   Tensile strength, psi337 267 No data** No data*** Elongation at break, % 885 680 >1250 Nodata*** Modulus, psi 109 95 41 No data*** Tear strength, Ibf/in 98 74 33No data*** Tg of polyurethane −28.3 −33.4 −39.8 −51.2  product, ° C. 55*the hardness was tested by type Shore 00 Durometer No data** data couldnot be obtained due to specimen were not broken after strain was over1200% No data*** for sample A4, it is too soft and tacky to be tested

TABLE 9 Comp. Ex. B1 B2 B3 B4 Krasol LBH 2000 LO 100 75 50 0Polyfarnesene diol 0 25 50 100 2-ethyl-1,3-hexanediol 11.87 11.58 11.2810.81 2,4′ Diphenylmethane 31.49 31.63 31.79 32.28 Diisocyanate 20% T-12solution in DBP, 4 5 5 4 drops Hard segment content, wt % 30.24 30.1730.10 30.11 Hardness of PU, Shore A 72 66 60 55 Tensile strength, psi1920 1029 742 572 Elongation at break, % 584 468 479 412 Modulus, psi494 332 228 164 Tear strength, Ibf/in 269 214 172 109 Tg of polyurethaneproduct, ° C. −28.0 −31.0 −36.6 −47.5

TABLE 10 Comp. Ex. C1 C2 C3 C4 Krasol LBH 2000 LO 100 75 50 0Polyfarnesene diol 0 25 50 100 2-ethyl-1,3-hexanediol 20.19 19.89 19.5919.01 2,4′ Diphenylmethane 46.19 46.33 46.48 46.77 Diisocyanate 20% T-12solution in DBP, 4 5 5 4 drops Hard segment content, wt % 39.90 39.8439.78 39.68 Hardness of PU, Shore A 83 75 73 71 Tensile strength, psi2188 1350 1125 982 Elongation at break, % 491 291 328 347 Modulus, psi860 681 527 378 Tear strength, Ibf/in 392 332 280 174 Tg of polyurethaneproduct, ° C. −26.6 −29.9 −33.0 −45.9

While increased concentrations of polyfarnesene diol in the polyol blendresulted in lower hardness and tensile strength in the cured samples,the higher concentration of chain extender substantially improved thephysical properties of all samples. Therefore, the appropriate selectionof the type and amount of chain extender should provide a polyurethaneprepolymer derived from a substantial amount of polyfarnesene diol withboth improved viscosity prior to curing and adequate physical propertiesupon curing.

Tables 11 to 16 below provide data associated with the physicalproperties of polyurethane samples prepared using the two-shot method.Polyols and isocyantes were reacted together to a form a prepolymer atapproximately 80° C. for about three hours followed by the addition ofchain extenders, such that the final polyurethane had an NCO/OH ratio ofapproximately 1.0. The final curing was performed in an oven and held at85° C. for 5 hours and overnight at 60° C.

For the samples of Examples D3-8, E3-8, and F3-8, polyfarnesene diol(Mw=5000) was evaluated having a higher molecular weight than thepolyfarnesene diol (Mw=2000) of Examples G3-8, H3-8, and I3-8. Eachsample sheet was post cured for one week at room temperature beforetesting of its physical properties. Relative parameters were tested byreferring to ASTM D412, ASTM D624 Die C, and using DSC, Shore typeDurometers, a Brookfield viscometer, and an EJA Vantage-10 tensiletester and the results provided in Tables 11 to 16.

TABLE 11 Comp. Ex. Example Example Example D1 D2 D3 D4 D5 D6 D7 D8Krasol ® LBH 2000 LO 100 100 75 75 50 50 0 0 Polyfarnesene diol 0 0 2525 50 50 100 100 2-ethyl-1,3-hexanediol 11.80 12.30 12.80 13.802,2,4-trimethyl-1,3- 11.80 12.30 12.80 13.80 pentanediol 2,4′Diphenylmethane 31.09 31.09 30.57 30.57 30.06 30.06 29.03 29.03Diisocyanate 20% T-12 in DBP, drop 3 3 3 3 3 3 3 3 Shore A/D hardness73/28 76/31 72/30 74/30 71/27 71/27 55/16 49/12 Tg, ° C. −29.0 −28.5−37.0 −38.6 −48.9 −47.3 −60.6 −62.4 Modulus, psi 339 372 474 387 442 452171 121 Tensile strength, psi 1136 675 1508 641 1507 816 657 447Elongation at break, % 862 779 730 634 665 526 473 744 Tear resistance,lbf/in 238 205 275 213 248 212 121 104

TABLE 12 Comp. Ex. Example Example Example E1 E2 E3 E4 E5 E6 E7 E8Krasol ® LBH 2000 LO 100 100 75 75 50 50 0 0 Polyfarnesene diol 0 0 2525 50 50 100 100 2-ethyl-1,3-hexanediol 20.40 21.00 21.63 22.502,2,4-trimethyl-1,3- 20.40 21.00 21.63 22.50 pentanediol 2,4′Diphenylmethane 46.17 46.17 45.82 45.82 45.54 45.54 44.28 44.28Diisocyanate 20% T-12 in DBP, drops 3 3 3 3 3 3 3 3 Shore A/D hardness91/48 91/44 87/42 86/40 82/38 83/35 66/21 63/18 Tg, ° C. −26.8 −30.0−36.6 −40.8 −45.5 −46.1 −62.1 −61.5 Modulus, psi 1163 1146 1118 10681043 977 387 323 Tensile strength, psi 2106 1347 1976 1345 1671 1191 602520 Elongation at break, % 452 383 453 399 343 272 200 314 Tearresistance, lbf/in 464 378 404 369 351 283 116 110

TABLE 13 Comp. Ex. Example Example Example F1 F2 F3 F4 F5 F6 F7 F8Krasol ® LBH 2000 LO 100 100 75 75 50 50 0 0 Polyfarnesene diol 0 0 2525 50 50 100 100 2-ethyl-1,3-hexanediol 32.60 33.10 33.60 34.602,2,4-trimethyl-1,3- 32.60 33.10 33.60 34.60 pentanediol 2,4′Diphenylmethane 67.55 67.55 67.03 67.03 66.52 66.52 65.49 65.49Diisocyanate 20% T-12 solution in DBP, 3 3 3 3 3 3 3 3 drops Shore A/Dhardness 95/58 96/57 92/52 94/48 82/39 89/42 72/19 68/18 Tg, ° C. −31.3−29.2 −41.5 −38.6 −50.3 −49.2 −62.9 −62.2 Modulus, psi 2160 2099 18411784 1581 1400 258 No data Tensile strength, psi 3093 2207 2305 18511834 1449 262 242 Elongation at break, % 429 290 338 232 231 186 133 88Tear resistance, lbf/in 627 561 498 463 362 283 80 64

TABLE 14 Comp. Ex. Example Example Example G1 G2 G3 G4 G5 G6 G7 G8Krasol ® LBH 2000 LO 100 100 75 75 50 50 0 0 Polyfarnesene diol 0 0 2525 50 50 100 100 2-ethyl-1,3-hexanediol 11.80 11.60 11.40 11.002,2,4-trimethyl-1,3- 11.80 11.60 11.40 11.00 pentanediol 2,4′Diphenylmethane 31.09 31.09 31.29 31.29 31.51 31.51 31.91 31.91Diisocyanate 20% T-12 in DBP, drops 3 3 3 3 3 3 3 3 Shore A/D hardness73/28 76/31 69/26 68/23 66/19 62/20 58/15 57/15 Tg, ° C. −29.0 −28.5−32.6 −33.5 −38.8 −37.3 −55.5 −49.7 Modulus, psi 339 372 320 274 219 21298 68 Tensile strength, psi 1136 675 1267 635 1048 560 577 314Elongation at break, % 862 779 833 728 939 760 903 866 Tear resistance,lbf/in 238 205 211 202 157 142 77 64

TABLE 15 Comp. Ex. Example Example Example H1 H2 H3 H4 H5 H6 H7 H8Krasol ® LBH 2000 LO 100 100 75 75 50 50 0 0 Polyfarnesene diol 0 0 2525 50 50 100 100 2-ethyl-1,3-hexanediol 20.40 20.20 20.00 19.602,2,4-trimethyl-1,3- 20.40 20.20 20.00 19.60 pentanediol 2,4′Diphenylmethane 46.17 46.17 46.37 46.37 46.58 46.58 46.98 46.98Diisocyanate 20% T-12 in DBP, drops 3 3 3 3 3 3 3 3 Shore A/D hardness91/48 91/44 88/41 88/40 82/36 88/39 84/35 84/37 Tg, ° C. −26.8 −30.0−33.9 −34.3 −39.0 −40.2 −48.11 −50.46 Modulus, psi 1163 1146 1059 1026801 830 687 714 Tensile strength, psi 2106 1347 1869 1586 1659 1291 14771027 Elongation at break, % 452 383 460 490 548 483 514 396 Tearresistance, lbf/in 464 378 395 385 346 326 260 240

TABLE 16 Comp. Ex. Example Example Example I1 I2 I3 I4 I5 I6 I7 I8Krasol ® LBH 2000 LO 100 100 75 75 50 50 0 0 Polyfarnesene diol 0 0 2525 50 50 100 100 2-ethyl-1,3-hexanediol 32.50 32.30 32.10 31.702,2,4-trimethyl-1,3- 32.50 32.30 32.10 31.70 pentanediol 2,4′Diphenylmethane 67.38 67.38 67.58 67.58 67.79 67.79 68.19 68.19Diisocyanate 20% T-12 in DBP, drop 3 3 3 3 3 3 3 3 Shore A/D hardness95/58 96/57 92/49 95/53 95/48 85/48 96/55 95/52 Tg, ° C. −31.3 −29.2−35.9 −34.5 −36.7 −41.3 −62.1 −63.6 Modulus, psi 2160 2099 1955 19151824 1710 1623 1557 Tensile strength, psi 3093 2207 2415 2133 3230 17612355 1669 Elongation at break, % 429 290 314 280 425 235 329 203 Tearresistance, lbf/in 627 561 564 542 527 471 427 420

Similar to the samples obtained by the one-shot procedure, increasedconcentrations of polyfarnesene diol in the polyol blend resulted inlower hardness and tensile strength in the cured samples. The use of2-ethyl-1,3-hexanediol instead of 2,2,4-trimethyl-1,3-pentanediolprovided improved physical properties of all samples suggesting that theappropriate selection of the type and amount of chain extender maycounter the effects of increasing the concentration of farnesene-basedsoft segments in the polyurethane.

B1, B2, B3, and B4 were prepared by the one shot procedure and had ahard segment content (chain extender plus diisocyanate) based on thetotal weight of the composition of about 30 wt %. G1, G3, G5, and G7also had a hard segment content of about 30 wt %, but were produced bythe two-shot method. G1, G3, G5, and G7 exhibited a slightly improvedtensile strength. Increasing the hard segment content generally improvedoverall physical performance. For example, compare C1, C2, C3, and C4with H1, H3, H5, and H7, which all have a hard segment content of about40 wt. %.

While preferred embodiments of the invention have been shown anddescribed herein, it will be understood that such embodiments areprovided by way of example only. Numerous variations, changes, andsubstitutions will occur to those skilled in the art without departingfrom the spirit of the invention. Accordingly, it is intended that theappended claims cover all such variations as fall within the spirit andscope of the invention.

What is claimed:
 1. A method of preparing a polyurethane comprising:combining one or more polyols with one or more isocyanate-containingcompounds having a isocyanate functionality of at least two to form areaction mixture, and curing the reaction mixture to produce apolyurethane which has a backbone derived from monomers comprisingfarnesene, wherein at least one of the one or more polyols is afarnesene-based polyol which is a polyol of a farnesene homopolymer or apolyol of a copolymer of farnesene and a comonomer selected from thegroup consisting of dienes, vinyl aromatics, and combinations thereof,the farnesene-based polyol being a polymer having a backbone derivedfrom monomers comprising farnesene and at least one terminal endcomprising a hydroxyl group.
 2. The method of claim 1, furthercomprising combining the one or more polyols and one or moreisocyanate-containing compounds with a chain extender.
 3. The method ofclaim 1, wherein the chain extender is selected from the groupconsisting of monomeric polyols and polyamines.
 4. The method of claim1, wherein the chain extender is selected from the group consisting of1,4-butanediol, 1,6-hexanediol, ethylene glycol, 2-ethyl-1,3-hexanediol(EHD), 2-butyl-2-ethyl-1,3-propanediol (BEPG),2,2,4-trimethyl-1,3-pentanediol (TMPD), 2,4-deithyl-1,5-pentanediol(PD-9), N,N-diisopropanol aniline, dimethylolpropionic acid,hydroquinone dihydroxyethyl ether (HQEE), diethylene glycol, propyleneglycol, trimethylolpropane, glycerol, diethyltoluenediamine (DETDA),4,4′-methylene bis(2-chloroaniline) (MBCA), ethylenediamine (EDA),dimethylthiotoluene-diamine (DMTTDA), 4,4′-methylenedianiline (MDA),complex of methylenediamine with NaCI (MDA complex), trimethyleneglycoldi-p-aminobenzoate (TMGDAB),4,4′-methylene-bis(3-chloro-2,6-diethylaniline) (M-CDEA),N,N′-bis(sec-butyl)methylene-dianiline (SBMDA), and mixtures thereof. 5.The method of claim 1, wherein the farnesene-based polyol is a polyol ofa copolymer of farnesene and one or more monomers selected from thegroup consisting of dienes, vinyl aromatics, and combinations thereof.6. The method of claim 5, wherein the dienes are selected from the groupconsisting of butadiene and isoprene.
 7. The method of claim 5, whereinthe vinyl aromatics are selected from the group consisting of styreneand alpha methyl styrene.
 8. The method of claim 1, wherein the one ormore isocyanate-containing compounds are selected from the groupconsisting of 4,4′-diphenylmethane diisocyanate (MDI),cyclohexanediisocyanate, p-phenylene diisocyanate, 1,5-naphthalenediisocyanate, toluene diisocyanate (TDI), p-xylene diisocyanate,hexamethylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate,1,4-bis(isocyanomethyl)- cyclohexane, p-tetramethylxylene diisocyanate,m-tetramethylxylene diisocyanate, isophorone diisocyanate, andcombinations thereof.
 9. The method of claim 1, wherein thefarnesene-based polyol has been hydrogenated to have a degree ofunsaturation less than or equal to 50% of the degree of unsaturation ofthe farnesene-based polyol prior to hydrogenation.
 10. The method ofclaim 1, wherein the farnesene-based polyol has been hydrogenated tohave a degree of unsaturation less than or equal to 10% of the degree ofunsaturation of the farnesene-based polyol prior to hydrogenation. 11.The method of claim 1, wherein the method comprises forming a prepolymerby reacting the one or more polyols with the one or moreisocyanate-containing compounds.
 12. The method of claim 11,additionally comprising chain-extending the prepolymer with one or morechain extenders.
 13. The method of claim 12, wherein the methodcomprises combining the one or more polyols, the one or moreisocyanate-containing compounds, and, optionally, one or more chainextenders generally simultaneously into a common reaction vessel to formthe reaction mixture.
 14. The method of claim 1, wherein the curingcomprises a hot air post-cure for up to twenty-four hours at 25° C. toabout 200° C.
 15. The method of claim 1, wherein curing is acceleratedusing a catalyst.